1. Field of the Invention
The present invention relates generally to a viscous fluid type heat generator in which a viscous fluid is subjected to a repeated shearing action to generate heat which is in turn transmitted to a circulating heat-transfer fluid in a heat receiving chamber, and is carried by the heat-transfer fluid to a desired heated area, such as a passenger compartment in an automobile. More particularly, the present invention relates to a viscous fluid type heat generator having such a construction thereof allowing it to be easily mounted on a small mounting area available in an engine compartment of an automobile.
2. Description of the Related Art
Japanese Unexamined Patent Publication (Kokai) No. 2-246823 (JP-A-2-246823) discloses a typical automobile heating system in which a viscous fluid type heat generator to generate heat is incorporated. The viscous fluid type heat generator disclosed in JP-A-2-246823 includes a pair of mutually opposing front and rear housings tightly secured together by appropriate tightening elements, such as through bolts to define an inner heat generating chamber and a heat receiving chamber arranged adjacent to the heat generating chamber but separated by a partition wall through which the heat is exchanged between the viscous fluid in the heat generating chamber and the water in the heat receiving chamber. The heat exchanging water is introduced into the heat receiving chamber through a water inlet port and delivered from the heat receiving chamber toward an external heating system, and the water is constantly circulated through the heat generator and the external heating system.
A drive shaft is rotatably supported in the front housing via an anti-friction bearing so as to support thereon a rotor element in such a manner that the rotor element is rotated with the drive shaft within the heat generating chamber. The rotor element has outer faces which are face-to-face with the wall faces of the heat generating chamber and form labyrinth grooves therebetween, and a viscous fluid, for example, silicone oil is supplied into the heat generating chamber so as to fill the labyrinth grooves between the rotor and the wall faces of the heating chamber.
When the drive shaft of the viscous fluid type heat generator incorporated in the automobile heating system is driven by an automobile engine, the rotor is also rotated within the heat generating chamber so as to apply a shearing action to the viscous fluid held between the wall surface of the heat generating chamber and the outer surface of the rotor. Thus, the viscous fluid generates heat due to the shearing action. The heat is transmitted to the heat exchanging water flowing through the heat receiving chamber. The heat exchanging water carries the heat to the heating circuit of the automobile heating system
Nevertheless, in the above-mentioned viscous fluid type heat generator of JP-A-2-246823, the drive shaft, driven by the car engine to rotate the rotor, has only one end outwardly projecting from one end of the housing of the heat generator, i.e., a rear end of the housing. A front end of the housing is provided with an inlet and an outlet for the heat exchanging liquid. The outwardly projecting end of the drive shaft is used for receiving a drive force from the engine via an appropriate transmission mechanism. Thus, the viscous fluid type heat generator must be mounted in an engine compartment at a location allowing the projecting end of the drive shaft to be operatively engaged with the car engine system. Since the engine compartment is generally narrow, the above-mentioned limit on the location of the viscous fluid type heat generator within the narrow engine compartment makes it difficult to obtain an appropriate mounting area for the viscous fluid type heat generator with respect to various types of automobiles and cars.
Generally, in the engine compartment, auxiliary equipment such as a compressor for a car air-conditioner, a water pump, a hydraulic pump for a power steering system, an alternator, an idler, are mounted therein. Each piece of the auxiliary equipment is arranged to be driven by the car engine through engagement between a common pulley on the engine crank shaft and an individual pulley of the auxiliary equipment via a belt. Therefore, the narrow engine compartment is occupied by these closely mounted auxiliary equipment without leaving any open area. Further, since automobiles must have reduced weight, the compact mounting of the above-mentioned auxiliary equipment becomes an important subject for designing and manufacturing engineers.
In the above-mentioned situation, when it is required to mount the viscous fluid type heat generator of the type as disclosed in JP-A-2-246823 in which the projecting end of the drive shaft of the heat generator, projecting from the rear end of the heat generator housing, supports thereon a hub element of a solenoid clutch for disconnectably connecting the viscous fluid type heat generator to the car engine, the viscous fluid type heat generator must be treated as an additional piece of auxiliary equipment with respect to the various existing auxiliary equipment. Thus, the designing and manufacturing engineers must rearrange the location of the auxiliary equipment mounted in the car engine compartment. This fact obviously brings about an inconvenience in that the automobile body must be re-designed, which causes an unfavorable increase in the manufacturing cost of the automobile.